The purpose of this procurement is to conduct multiple early phase (Phase 1 and Phase 2) clinical trials of the National Cancer Institute (NCI), Division of Cancer Prevention (DCP)-sponsored cancer preventive agents and to establish the infrastructures composed of one or more collaborating institutions that will perform these trials. The trials will assess the cancer preventive potential of various agents by evaluating the biologic effects of these agents on their molecular targets and by determining clinically relevant correlates.